This Mentored Patient-Oriented Research Career Development Award will enable Dr. Christopher-Stine to acquire the vital methodologic skills and expertise to become an independent clinical investigator, focusing on the idiopathic inflammatory myopathies (IIM). The PI will combine her growing research experience and continued training in public health with the mentorship of Drs. Allan Gelber, Antony Rosen, and Paul Plotz. IIM, including dermatomyositis, polymyositis, and inclusion body myositis, constitute the largest subset of acquired myopathies and often affect adults in their prime. A major limitation of prior studies is the poor specificity of the diagnostic criteria used to classify IIM. The therapeutic implication for such misclassified patients is substantial. Thus, it is crucial to sharpen conventional classification criteria so that therapy is used appropriately. The published literature in IIM is also characterized by few formal prospective myositis cohort studies, yielding sparse evidence by which to reliably predict meaningful outcomes. To address and to overcome these important methodologic limitations in IIM, Dr. Christopher-Stine will interrogate the valuable NIH Protocol entitled "Studies in Natural History and Pathogenesis of Polymyositis and Dermatomyositis and Related Diseases." An Associate Investigator to this protocol, Dr. Christopher-Stine has participated in patient evaluations and is currently formally organizing the demographic, clinical, serologic, and radiographic data collected on 672 patients enrolled in the protocol since 1991. To date, no formal epidemiologic database has been established using this resource. This application proposes to access, organize and establish this protocol into a systematic relational database which will be utilized to address the following Specific Aims: (1) To determine the sensitivity and specificity of Magnetic Resonance Imaging (MRI) to discriminate among IIM, muscular dystrophy, and normal muscle;(2) To determine the diagnostic value of novel genetic expression profiling among patients presenting with a myositis phenotype who remain undiagnosed after utilizing conventional diagnostic classification schema;(3) To define longitudinal predictors of mortality, disability, and malignancy. With support from this award, the invaluable complementary mentorship skills, and the expertise of the listed collaborators, Dr. Christopher-Stine is poised to develop and launch her independent clinical research career.